Expression of SOX4 in ATL. (A) RT-PCR analysis of ATL cell lines. Semiquantitative RT-PCR was performed to analyze expression of SOX4, FRA-2, and JUND in 6 ATL cell lines. Normal PBMCs treated with PHA for 3 days (PHA-PBMC) and Raji, a Burkitt lymphoma cell line, were also included. GAPDH was used as a loading control. The representative results from 3 separate experiments are shown. (B) Immunoblot analysis. Cell extracts prepared from 2 ATL cell lines and Raji were subjected to immunoblot analysis. After electrophoresis and electrotransfer, blotted filters were reacted with anti-SOX4 or anti–α-tubulin. The representative results from 3 separate experiments are shown. (C) Immunocytochemistry. Two ATL cell lines and Raji were used. Cells were fixed and stained with anti-SOX4 or control IgG. Cells were counterstained with DAPI. The representative results from 3 separate experiments are shown. Original magnification, ×800. (D) RT-PCR analysis of primary cells. Semiquantitative RT-PCR was performed to analyze expression of SOX4, FRA-2, and JUND in normal CD4⁺ T cells and primary ATL cells (>90% leukemia cells). GAPDH was used as a loading control. The representative results from 3 separate experiments are shown. (E) Immunohistochemistry. Tissue sections of inflamed tonsils (n = 2) and ATL skin lesions (n = 7) were stained with anti-SOX4 or control IgG. The representative results are shown. Original magnification, ×400. HE, hematoxylin-eosin; PHA, phytohemagglutinin.